Our QA reported an oops in the ext4_mb_release_group_pa tracing, and Josef Bacik pointed out that it was because we may have a non-null but uninitialized ac_inode in the allocation context. I can reproduce it when running xfstests with ext4 tracepoints on, on a CONFIG_SLAB_DEBUG kernel. We call trace_ext4_mb_release_group_pa from 2 places, ext4_mb_discard_group_preallocations and ext4_mb_discard_lg_preallocations In both cases we allocate an ac as a container just for tracing (!) and never fill in the ac_inode. There's no reason to be assigning, testing, or printing it as far as I can see, so just remove it from the tracepoint. Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> --- diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index 01e9e00..e352c77 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -432,7 +432,6 @@ TRACE_EVENT(ext4_mb_release_group_pa, TP_STRUCT__entry( __field( dev_t, dev ) - __field( ino_t, ino ) __field( __u64, pa_pstart ) __field( __u32, pa_len ) @@ -440,8 +439,6 @@ TRACE_EVENT(ext4_mb_release_group_pa, TP_fast_assign( __entry->dev = sb->s_dev; - __entry->ino = (ac && ac->ac_inode) ? - ac->ac_inode->i_ino : 0; __entry->pa_pstart = pa->pa_pstart; __entry->pa_len = pa->pa_len; ), -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
